1. Field of the Invention
The invention relates to suction cleaners, and in particular to a separator for a suction cleaner. In one of its aspects, the invention relates to a separator with a cyclonic airflow path to separate dirt and debris from air drawn into the cleaner. In another of its aspects, the invention relates to a separator that deposits the dirt and debris in a collection receptacle. In another of its aspects, the invention relates to a bottom discharge dirt-collecting bin with an integrated filter chamber. In another of its aspects, the invention relates to a separator including structure for inhibiting the re-entrainment of debris that vacillates with upward airflows in the collection receptacle.
2. Description of the Related Art
Cyclone separators are well known. Some follow the textbook examples using frusto-conical shape separators and others use high-speed rotational motion of the air/dirt to separate the dirt by centrifugal force. Typically, working air enters and exits at an upper portion of the cyclone separator as the bottom portion of the cyclone separator is used to collect debris. Furthermore, in an effort to reduce weight, the motor/fan assembly that creates the working air flow is typically placed at the bottom of the handle, below the cyclone separator. This arrangement therefore, requires a tortuous air path from the top of the cyclone assembly, down the handle to the inlet of the motor/fan assembly. This creates a long air path with multiple parts which may allow for air leaks and generally negatively impacting airflow and, necessarily, cleaning performance.
Conrad et al., in U.S. Pat. No. 6,129,775 discloses a cyclone separator with at terminal insert which can take a number of forms. In FIG. 14(d), the terminal insert may comprise a plurality of longitudinally extending members (such as rods), which extend upwardly into the cyclone separator cavity from the bottom surface of the cyclone separator. The rods are said to interact with circulating fluid 48 to disrupt its rotational motion. The rods may be positioned symmetrically non-symmetrically around longitudinal axis of the separator. The rods may be a variety of shapes such as, in transverse section, squares, ellipses or other closed convex or abode shapes. Further, the transverse section of rods may vary longitudinally.
BISSELL Homecare, Inc. presently manufactures and sells in the United States an upright vacuum cleaner that has a cyclone separator and a dirt-collecting bin or dirt cup. A horizontal plate separates the cyclone separator from the dirt cup. The air flowing through the cyclone separator passes through an annular cylindrical cage with baffles and through a cylindrical filter before exiting the cyclone separator at the upper end thereof. The dirt cup has three finger-like projections extending upwardly from the bottom thereof to agglomerate the dirt in the dirt cup. The dirt cup further has a pair of radial fins extending inwardly from the side walls of the dirt cup. The dirt cup and the cyclone separator is further disclosed in the co-pending U.S. patent application Ser. No. 10/058,514, filed Jan. 28, 2002, and published as US20040154126 which is incorporated herein by reference.
U.S. Pat. No. 6,070,291 to Bair et al. and its progeny attempts to solve the efficiency problem by shortening the air path from the cyclone exhaust to the motor inlet. These patents disclose a pleated main filter element in a cyclonic chamber whereby exhaust air is drawn through the main filter through the bottom of the cyclonic chamber, through a secondary filter and directly into the motor/fan inlet. The motor/fan assembly is in a vertical position below the cyclone which is undesirable due to the amount of space needed at the bottom of the handle.
U.S. Pat. No. 6,341,404 to Salo et al. discloses a bottom discharge cyclone chamber with the motor/fan assembly mounted horizontally below the cyclone chamber. However, motor exhaust air is redirected back up towards the bottom of the cyclone chamber where it exits the unit through a cylindrical filter in a radial fashion. This path introduces a number of turns which tends to create backpressure and therefore reduce efficiency.
U.S. Pat. No. 4,593,429 to Dyson discloses a two stage cyclonic separator in a vacuum cleaner with a standpipe that extends from the outlet of a secondary cyclone separator through a bottom wall of a removable dirt cup. Air in a secondary cyclone separator exits the secondary cyclone through the standpipe to a vacuum source